By PAUL NEWBERRY
LONDON (AP) -- The greatest?
When it comes to Michael Phelps, the answer seems obvious with just a cursory glance of the medals table. The guy has won 15 golds -- "insane," says Serena Williams, who certainly knows a thing or two about winning -- and now he's got more total Olympic medals than anyone, with a few more races to extend the record into almost unfathomable territory before he's done in London.
Even President Barack Obama jumped on the bandwagon, phoning Phelps on Wednesday to congratulate him on his remarkable accomplishment.
"He's definitely the greatest Olympian of all time," said South African swimmer Chad le Clos, who's actually one of the few guys to have beaten Phelps at the Olympics. "He's my idol."
But the greatest?
That's where things get a bit dicier.
While the sporting world -- everyone from Masters champion Bubba Watson to Spanish soccer star Gerard Pique -- peppered Phelps with praise in the Twitter-verse after he earned the 19th medal of his career, no less an authority than Sebastian Coe was reticent to bestow the ultimate crown.
"My personal view is I'm not sure he's the greatest," Lord Coe said on Wednesday, speaking as a two-time gold medalist in athletics and the face of these games as head of the London organizing committee. "But he's certainly the most successful."
Other think the sheer magnitude of Phelps' accomplishments leave little doubt about his place in history.
"He's won more medals that any Olympian in history," said U.S. swimmer Tyler Clary. "That should speak for itself."
Indeed, the numbers are mind-boggling:
-- Start with the golds. Phelps has six more than anyone else. If he wins his last three events in London, he'll have twice as many as anyone else.
-- Soviet-era gymnast Larisa Latynina previously held the record for total medals, winning 18 over a span of three Olympics from 1956-64. From there, the dropoff is significant. Next on the list is another Soviet gymnast, Nikolai Andrianov, with 15 medals. Three others captured 13. Just 23 more -- in both Summer and Winter Games -- have as many as 10. If Phelps was a nation, he would be tied for 57th on the Summer Games medal list and closing in on India, the second-most populous nation on the globe.
-- Phelps won the most gold medals at a single games, his eight-race sweep in Beijing four years ago. In retrospect, the Great Haul of China looks even more impressive. While it's said that every record is made to be broken, it's hard to see anyone topping that mark. Equaling it at best, and that will be tough enough.
Williams, who is competing in the Olympic tennis competition at Wimbledon, described Phelps as "the ultimate Olympian."
"I mean, who does that?" she asked. "No one else could do that. It's insane."
In London, Phelps has been a bit of letdown. He didn't even make the podium in his first race, laboring home fourth in the 400 individual medley, and he settled for the first two silvers of his career, including a shocking loss to le Clos in the 200 butterfly Tuesday. But he finally got his first gold of these games in the 4x200 freestyle relay, taking over with a big lead and cruising home while the roar inside the Olympic Aquatics Centre got louder with each powerful stroke.
Afterward, the announcer proclaimed him "a complete legend" while the Foo Fighters song "Best of You" blared from the speakers. Someone held up a bed sheet with the handwritten message "PHELPS GREATEST OLYMPIAN EVER."
That seemed to be the general sentiment around the Olympic city, a day after Phelps captured No. 19.
From the shooting range: "Yes, for me he is the greatest," said Chinese shooter Chen Ying, shortly after winning silver in women's 25-meter pistol. "Michael Phelps is a role model for all athletes in the world. In swimming, competition is like a battlefield. He inspires others to go for gold as well."
From the beach volleyball stadium: "For sure," Natacha Rigobert of Mauritius said, "because he won so many medals swimming for the USA and to keep doing good like this is amazing. I mean, nobody did that before. It's great."
From the world of athletics: "Once you do something that nobody has ever done before, it automatically puts you in that category," retired sprinter Maurice Greene said. "It's an arguable debate, but he has to be in the top."
Coe begs to disagree. Sort of.
"This is the great global pub game. Who is the greatest athlete of all time?" he said during his daily briefing. "Whether he's the greatest, I don't know. I could go around this whole room and we'd come up with different interpretations. You'd have to say he's up there. Is he the greatest? In my opinion, probably not. But my opinion means no more than anyone else's."
Coe was pressed for his choice. If not Phelps, who?
"I could throw out a whole series of names," Coe said. "I could throw out Steve Redgrave, Daley Thompson," a couple of home-country faves. "If I wanted to go back a few generations and recall what Jesse Owens did in 1936, it was unbelievable. Nadia Comaneci. I don't know. It's the great local pub game."
International Olympic Committee president Jacques Rogge also was hesitant to put Phelps above everyone else.
"Definitely one of the greatest," Rogge told The Associated Press. "You cannot reduce everything to the medals. What Larisa Latynina has done with 18 medals and Michael has done with 19 medals is unequaled and is probably going to stay like this for decades to come. But there are other issues that both have. Personality. Larisa is a wonderful personality. Michael is a wonderful personality. There are great iconic athletes who have not won that many medals, but definitely it is a landmark."
Rogge, too, was pushed to name others he would put alongside Phelps.
"I'm not going to make an exhaustive list," he replied, "but there are legendary athletes like Paavo Nurmi, Carl Lewis and Jesse Owens and many more that are really idols and icons of the sport."
Indeed, it's worth noting that Phelps participates in a sport where it's possible to win multiple events at a single games. Compare that with someone such as basketball star LeBron James, who is at the top of his game but can only win one gold medal -- no more than one medal, period -- every four years. And while Phelps swims an impressive array of events, encompassing all four strokes and ranging in distance from 100 to 400 meters, it's hard to discount Nurmi winning five gold medals at the 1924 Games, including the 1,500 and 5,000 less than two hours apart. Lewis has to be considered for his versatility, winning everything from sprints to relays to the long jump.
"There are a ton of athletes that are in the conversation," Greene said. "You could debate it for hours and hours. It's hard to say someone is THE greatest. You have different eras. Eight years from now, it might be someone who comes by and does something far greater than (Phelps) did, in a different event and a different sport and get more gold medals than that."
But Greene added: "In this era, I'd give it to him."
Hard to argue with that.
AP Sports Writer Jon Krawczynski, Janie McCauley, Eric Willemsen, Beth Harris, Pat Graham, Steve Wilson and Chris Torchia contributed to this report.